You probably have bad paint. We have been conditioned to believe "you get what you pay for" and we think that paintballs are the same way.
But, paintballs are THE MOST IMPORTANT thing we buy as they directly affect our accuracy. And if you love a certain brand, that doesn't mean that it will be the same every time you go into the store to buy it!
The other thing to consider is if your buying paint from a big box store, like this video said, It may just be old as hell. It takes a lot longer to move these boxes through the big stores. My local field gets a fresh skid every week and that helps. Just because its expensive and curves doesnt mean its a bad paintball, just means it may be old. I agree, check boxes and bags and if possible, know where you are buying from.